One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
FUNCTIONAL BLOCK DIAGRAM
INPUT
POWER
SUPPLY
19
14
15
16
17
18
V
O
30
29
T2
POWER
POWER
OSCILLATOR
INPUT
OUTPUT
MOD
DEMOD
FILTER
1
2
OUTPUT
POWER
SUPPLY
3
4
O
COM
+V
OSS
V
OSS
AD210
PWR COM
PWR
T3
T1
V
ISS
+V
ISS
I
COM
+IN
IN
FB
a
Precision, Wide Bandwidth
3-Port Isolation Amplifier
AD210*
FEATURES
High CMV Isolation: 2500 V rms Continuous
3500 V Peak Continuous
Small Size: 1.00" 2.10" 0.350"
Three-Port Isolation: Input, Output, and Power
Low Nonlinearity: 0.012% max
Wide Bandwidth: 20 kHz Full-Power (3 dB)
Low Gain Drift: 25 ppm/ C max
High CMR: 120 dB (G = 100 V/V)
Isolated Power: 15 V @ 5 mA
Uncommitted Input Amplifier
APPLICATIONS
Multichannel Data Acquisition
High Voltage Instrumentation Amplifier
Current Shunt Measurements
Process Signal Isolation
GENERAL DESCRIPTION
The AD210 is the latest member of a new generation of low
cost, high performance isolation amplifiers. This three-port,
wide bandwidth isolation amplifier is manufactured with sur-
face-mounted components in an automated assembly process.
The AD210 combines design expertise with state-of-the-art
manufacturing technology to produce an extremely compact
and economical isolator whose performance and abundant user
features far exceed those offered in more expensive devices.
The AD210 provides a complete isolation function with both
signal and power isolation supplied via transformer coupling in-
ternal to the module. The AD210's functionally complete de-
sign, powered by a single +15 V supply, eliminates the need for
an external DC/DC converter, unlike optically coupled isolation
devices. The true three-port design structure permits the
AD210 to be applied as an input or output isolator, in single or
multichannel applications. The AD210 will maintain its high
performance under sustained common-mode stress.
Providing high accuracy and complete galvanic isolation, the
AD210 interrupts ground loops and leakage paths, and rejects
common-mode voltage and noise that may other vise degrade
measurement accuracy. In addition, the AD210 provides pro-
tection from fault conditions that may cause damage to other
sections of a measurement system.
PRODUCT HIGHLIGHTS
The AD210 is a full-featured isolator providing numerous user
benefits including:
High Common-Mode Performance:
The AD210 provides
2500 V rms (Continuous) and
3500 V peak (Continuous) common-
mode voltage isolation between any two ports. Low input
capacitance of 5 pF results in a 120 dB CMR at a gain of 100,
and a low leakage current (2
A rms max @ 240 V rms, 60 Hz).
High Accuracy:
With maximum nonlinearity of
0.012% (B
Grade), gain drift of
25 ppm/
C max and input offset drift of
(
10
30/G)
V/
C, the AD210 assures signal integrity while
providing high level isolation.
Wide Bandwidth:
The AD210's full-power bandwidth of
20 kHz makes it useful for wideband signals. It is also effective
in applications like control loops, where limited bandwidth
could result in instability.
Small Size:
The AD210 provides a complete isolation function
in a small DIP package just 1.00"
2.10"
0.350". The low
profile DIP package allows application in 0.5" card racks and
assemblies. The pinout is optimized to facilitate board layout
while maintaining isolation spacing between ports.
Three-Port Design:
The AD210's three-port design structure
allows each port (Input, Output, and Power) to remain inde-
pendent. This three-port design permits the AD210 to be used
as an input or output isolator. It also provides additional system
protection should a fault occur in the power source.
Isolated Power:
15 V @ 5 mA is available at the input and
output sections of the isolator. This feature permits the AD210
to excite floating signal conditioners, front-end amplifiers and
remote transducers at the input as well as other circuitry at the
output.
Flexible Input:
An uncommitted operational amplifier is pro-
vided at the input. This amplifier provides buffering and gain as
required and facilitates many alternative input functions as
required by the user.
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
REV. A
*Covered by U.S. Patent No. 4,703,283.
AD210 PIN DESIGNATIONS
Pin
Designation
Function
1
V
O
Output
2
O
COM
Output Common
3
+V
OSS
+Isolated Power @ Output
4
V
OSS
Isolated Power @ Output
14
+V
ISS
+Isolated Power @ Input
15
V
ISS
Isolated Power @ Input
16
FB
Input Feedback
17
IN
Input
18
I
COM
Input Common
19
+IN
+Input
29
Pwr Com
Power Common
30
Pwr
Power Input
AD210SPECIFICATIONS
(typical @ +25 C, and V
S
= +15 V unless otherwise noted)
Model
AD210AN
AD210BN
AD210JN
GAIN
Range
1 V/V 100 V/V
*
*
Error
2% max
1% max
*
vs. Temperature(0
C to +70
C)
+25 ppm/
C max
*
*
(25
C to +85
C)
50 ppm/
C max
*
*
vs. Supply Voltage
0.002%/V
*
*
Nonlinearity
1
0.025% max
0.012% max
*
INPUT VOLTAGE RATINGS
Linear Differential Range
10 V
*
*
Maximum Safe Differential Input
15 V
*
*
Max. CMV Input-to-Output
*
ac, 60 Hz, Continuous
2500 V rms
*
1500 V rms
dc, Continuous
3500 V peak
*
2000 V peak
Common-Mode Rejection
*
60 Hz, G = 100 V/V
*
R
S
500
Impedance Imbalance
120 dB
*
*
Leakage Current Input-to-Output
*
@ 240 V rms, 60 Hz
2
A rms max
*
*
INPUT IMPEDANCE
Differential
l0
12
*
*
Common Mode
5 G
5 pF
*
*
INPUT BIAS CURRENT
Initial, @ +25
C
30 pA typ (400 pA max)
*
*
vs. Temperature (0
C to +70
C)
10 nA max
*
*
(25
C to +85
C)
30 nA max
*
*
INPUT DIFFERENCE CURRENT
Initial, @ +25
C
5 pA typ (200 pA max)
*
*
vs. Temperature(0
C to + 70
C)
2 nA max
*
*
(25
C to +85
C)
10 nA max
*
*
INPUT NOISE
Voltage (l kHz)
18 nV/
Hz
*
*
(10 Hz to 10 kHz)
4
V rms
*
*
Current (1 kHz)
0.01 pA/
Hz
*
*
FREQUENCY RESPONSE
Bandwidth (3 dB)
*
G = 1 V/V
20 kHz
*
*
G = 100 V/V
15 kHz
*
*
Settling Time (
10 mV, 20 V Step)
*
G = 1 V/V
150
s
*
*
G = 100 V/V
500
s
*
*
Slew Rate (G = 1 V/V)
1 V/
s
*
*
OFFSET VOLTAGE (RTI)
2
Initial, @ +25
C
15
45/G) mV max
(
5
15/G) mV max
*
vs. Temperature (0
C to +70
C)
(
10
30/G)
V/
C
*
*
(25
C to +85
C)
(
10
50/G)
V/
C
*
*
RATED OUTPUT
3
Voltage, 2 k
Load
10 V min
*
*
Impedance
1
max
*
*
Ripple (Bandwidth = 100 kHz)
10 mV p-p max
*
*
ISOLATED POWER OUTPUTS
4
Voltage, No Load
15 V
*
*
Accuracy
10%
*
*
Current
5 mA
*
*
Regulation, No Load to Full Load
See Text
*
*
Ripple
See Text
*
*
POWER SUPPLY
Voltage, Rated Performance
+15 V dc
5%
*
*
Voltage, Operating
+15 V dc
10%
*
*
Current, Quiescent
50 mA
*
*
Current, Full Load Full Signal
80 mA
*
*
TEMPERATURE RANGE
Rated Performance
25
C to +85
C
*
*
Operating
40
C to +85
C
*
*
Storage
40
C to +85
C
*
*
PACKAGE DIMENSIONS
Inches
1.00
2.10
0.350
*
*
Millimeters
25.4
53.3
8.9
*
*
NOTES
*Specifications same as AD210AN.
1
Nonlinearity is specified as a % deviation from a best straight line..
2
RTI Referred to Input.
3
A reduced signal swing is recommended when both
V
ISS
and
V
OSS
supplies are fully
loaded, due to supply voltage reduction.
4
See text for detailed information.
_
Specifications subject to change without notice.
REV. A
2
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
AC1059 MATING SOCKET
CAUTION
ESD (electrostatic discharge) sensitive device. Elec-
trostatic charges as high as 4000 V readily accumu-
late on the human body and test equipment and can
discharge without detection. Although the AD210
features proprietary ESD protection circuitry, per-
manent damage may occur on devices subjected to
high energy electrostatic discharges. Therefore,
proper ESD precautions are recommended to avoid
performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
AD210
REV. A
3
INSIDE THE AD210
The AD210 basic block diagram is illustrated in Figure 1.
A +15 V supply is connected to the power port, and
15 V isolated power is supplied to both the input and
output ports via a 50 kHz carrier frequency. The uncom-
mitted input amplifier can be used to supply gain or buff-
ering of input signals to the AD210. The fullwave
modulator translates the signal to the carrier frequency for
application to transformer T1. The synchronous demodu-
lator in the output port reconstructs the input signal. A
20 kHz, three-pole filter is employed to minimize output
noise and ripple. Finally, an output buffer provides a low
impedance output capable of driving a 2 k
load.
INPUT
POWER
SUPPLY
19
14
15
16
17
18
V
O
30
29
T2
POWER
POWER
OSCILLATOR
INPUT
OUTPUT
MOD
DEMOD
FILTER
1
2
OUTPUT
POWER
SUPPLY
3
4
O
COM
+V
OSS
V
OSS
AD210
PWR COM
PWR
T3
T1
V
ISS
+V
ISS
I
COM
+IN
IN
FB
Figure 1. AD210 Block Diagram
USING THE AD210
The AD210 is very simple to apply in a wide range of ap-
plications. Powered by a single +15 V power supply, the
AD210 will provide outstanding performance when used
as an input or output isolator, in single and multichannel
configurations.
Input Configurations:
The basic unity gain configura-
tion for signals up to
10 V is shown in Figure 2. Addi-
tional input amplifier variations are shown in the following
figures. For smaller signal levels Figure 3 shows how to
obtain gain while maintaining a very high input impedance.
19
14
15
16
17
18
V
OUT
(
10V)
30
29
+V
OSS
V
SIG
10V
AD210
+V
ISS
V
ISS
+15V
2
3
4
V
OSS
1
V
OUT
Figure 2. Basic Unity Gain Configuration
The high input impedance of the circuits in Figures 2 and
3 can be maintained in an inverting application. Since the
AD210 is a three-port isolator, either the input leads or
the output leads may be interchanged to create the signal
inversion.
19
14
15
16
17
18
30
29
+V
OSS
V
SIG
AD210
+V
ISS
V
ISS
+15V
2
3
4
V
OSS
1
V
OUT
= V
SIG
1+
( )
R
F
R
G
R
G
R
F
Figure 3. Input Configuration for G > 1
Figure 4 shows how to accommodate current inputs or sum cur-
rents or voltages. This circuit configuration can also be used for
signals greater than
10 V. For example, a
100 V input span
can be handled with R
F
= 20 k
and R
S1
= 200 k
.
19
14
15
16
17
18
30
29
+V
OSS
AD210
+V
ISS
V
ISS
+15V
2
3
4
V
OSS
1
R
S1
I
S
V
S2
V
S1
R
S2
R
F
V
OUT
V
OUT
= R
F
V
S1
R
S1
( )
V
S2
R
S2
+
+ I
S
+ ...
Figure 4. Summing or Current Input Configuration
Adjustments
When gain and offset adjustments are required, the actual cir-
cuit adjustment components will depend on the choice of input
configuration and whether the adjustments are to be made at
the isolator's input or output. Adjustments on the output side
might be used when potentiometers on the input side would
represent a hazard due to the presence of high common-mode
voltage during adjustment. Offset adjustments are best done at
the input side, as it is better to null the offset ahead of the gain.
Figure 5 shows the input adjustment circuit for use when the in-
put amplifier is configured in the noninverting mode. This offset
adjustment circuit injects a small voltage in series with the
19
15
16
17
18
30
29
+V
OSS
AD210
+V
ISS
V
ISS
+15V
2
3
4
V
OSS
R
G
HI
V
OUT
V
SIG
14
200
47.5k
5k
100k
50k
LO
GAIN
OFFSET
1
Figure 5. Adjustments for Noninverting Input
AD210
REV. A
4
low side of the signal source. This will not work if the source has
another current path to input common or if current flows in the
signal source LO lead. To minimize CMR degradation, keep the
resistor in series with the input LO below a few hundred ohms.
Figure 5 also shows the preferred gain adjustment circuit. The
circuit shows R
F
of 50 k
, and will work for gains of ten or
greater. The adjustment becomes less effective at lower gains
(its effect is halved at G = 2) so that the pot will have to be a
larger fraction of the total R
F
at low gain. At G = 1 (follower)
the gain cannot be adjusted downward without compromising
input impedance; it is better to adjust gain at the signal source
or after the output.
Figure 6 shows the input adjustment circuit for use when the
input amplifier is configured in the inverting mode. The offset
adjustment nulls the voltage at the summing node. This is pref-
erable to current injection because it is less affected by subse-
quent gain adjustment. Gain adjustment is made in the feedback
and will work for gains from 1 V/V to 100 V/V.
19
15
16
17
18
30
29
+V
OSS
AD210
+V
ISS
V
ISS
+15V
2
3
4
V
OSS
V
OUT
V
SIG
14
200
47.5k
5k
100k
GAIN
OFFSET
50k
R
S
1
Figure 6. Adjustments for Inverting Input
Figure 7 shows how offset adjustments can be made at the out-
put, by offsetting the floating output port. In this circuit,
15 V
would be supplied by a separate source. The AD210's output
amplifier is fixed at unity, therefore, output gain must be made
in a subsequent stage.
19
15
16
17
18
30
29
+V
OSS
AD210
+V
ISS
V
ISS
+15V
2
3
4
V
OSS
V
OUT
14
200
1
0.1F
100k
OFFSET
50k
+15V
15V
Figure 7. Output-Side Offset Adjustment
PCB
Layout for Multichannel Applications: The unique
pinout positioning minimizes board space constraints for multi-
channel applications. Figure 8 shows the recommended printed
circuit board layout for a noninverting input configuration with
gain.
R
F
R
G
R
F
R
G
R
F
R
G
POWER
CHANNEL INPUTS
1
2
3
0.1"
GRID
CHANNEL OUTPUTS
1
2
3
Figure 8. PCB Layout for Multichannel Applications with
Gain
Synchronization:
The AD210 is insensitive to the clock of an
adjacent unit, eliminating the need to synchronize the clocks.
However, in rare instances channel to channel pick-up may
occur if input signal wires are bundled together. If this happens,
shielded input cables are recommended.
PERFORMANCE CHARACTERISTICS
Common-Mode Rejection:
Figure 9 shows the common-
mode rejection of the AD210 versus frequency, gain and input
source resistance. For maximum common-mode rejection of
unwanted signals, keep the input source resistance low and care-
fully lay out the input, avoiding excessive stray capacitance at
the input terminals.
180
140
40
10 20 50 60 100 200 500 1k 2k 5k 10k
160
100
120
60
80
FREQUENCY Hz
R
LO
= 0
R
LO
= 500
R
LO
= 0
R
LO
= 10k
R
LO
= 10k
G = 100
G = 1
CMR dB
Figure 9. Common-Mode Rejection vs. Frequency
AD210
REV. A
5
+0.04
+0.03
+0.02
+0.01
0
0.01
0.02
0.03
0.04
10 8 6 4 2 0 +2 +4 +6 +8 +10
OUTPUT VOLTAGE SWING Volts
+8
+6
+4
+2
0
2
4
6
8
ERROR mV
ERROR %
Figure 12. Gain Nonlinearity Error vs. Output
0.01
0.009
0.008
0.007
0.006
0.005
0.004
0.003
0.002
0.001
0.000
100
90
80
70
60
50
40
30
20
10
0
0 2 4 6 8 10 12 14 16 18 20
TOTAL SIGNAL SWING Volts
ERROR % of Signal Swing
ERROR ppm of Signal Swing
Figure 13. Gain Nonlinearity vs. Output Swing
Gain vs. Temperature:
Figure 14 illustrates the AD210's
gain vs. temperature performance. The gain versus temperature
performance illustrated is for an AD210 configured as a unity
gain amplifier.
400
200
0
200
400
600
800
1000
1200
1400
1600
25 0 +25 +50 +70 +85
TEMPERATURE
C
GAIN ERROR ppm of Span
G = 1
Figure 14. Gain vs. Temperature
Phase Shift:
Figure 10 illustrates the AD210's low phase shift
and gain versus frequency. The AD210's phase shift and wide
bandwidth performance make it well suited for applications like
power monitors and controls systems.
60
20
80
100
100k
10k
1k
10
40
20
0
60
40
FREQUENCY Hz
0
20
40
60
80
100
120
140
PHASE SHIFT Degrees
GAIN dB
G = 1
G = 100
Figure 10. Phase Shift and Gain vs. Frequency
Input Noise vs. Frequency:
Voltage noise referred to the input
is dependent on gain and signal bandwidth. Figure 11 illustrates
the typical input noise in nV/
Hz
of the AD210 for a frequency
range from 10 to 10 kHz.
60
40
0
100
10k
1k
10
50
20
30
10
FREQUENCY Hz
NOISE nV/
Hz
Figure 11. Input Noise vs. Frequency
Gain Nonlinearity vs. Output:
Gain nonlinearity is defined as the
deviation of the output voltage from the best straight line, and is
specified as % peak-to-peak of output span. The AD210B provides
guaranteed maximum nonlinearity of
0.012% with an output span of
10 V. The AD210's nonlinearity performance is shown in Figure 12.
Gain Nonlinearity vs. Output Swing:
The gain nonlinearity
of the AD210 varies as a function of total signal swing. When
the output swing is less than 20 volts, the gain nonlinearity as a
fraction of signal swing improves. The shape of the nonlinearity
remains constant. Figure 13 shows the gain nonlinearity of the
AD210 as a function of total signal swing.
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